Media: Get a picture and get out fast: Journalists covering student riots in Paris found themselves under attack. Philip Jacobson explains why

When a protest march by thousands of students in Paris degenerated into violence last week, a cameraman for the state-owned France 2 network started to film gangs as they smashed shop windows and burnt parked cars. Philippe Turpaud was set upon and kicked and beaten so badly that he was carried away on a stretcher with a fractured skull. An Italian photographer was also worked over and other journalists fled from mobs threatening them as collabos - police informers.

These attacks came just a few days after the French weekly magazine Globe had revealed that two press photographs, clearly identifying youths ransacking a shop during a previous clash in Paris, were pinned on noticeboards in every police station in the capital. They had been supplied by Gamma, one of the world's leading picture agencies, and, contrary to normal practice, the features of the looters had not been obscured before distribution: 'The images that betray the wreckers,' trumpeted Globe.

In France, as in Britain, the media are reluctant to hand over material that might aid the authorities with the arrest or prosecution of alleged wrongdoers, though exceptions have been made in cases involving terrorism. Like their British counterparts, the French police may seek court orders compelling the surrender of specified material - most commonly photographs and videotapes of street trouble - and there are stiff penalties for organisations and individuals refusing to comply.

The misuse of Gamma's photos has attracted particular attention because French journalists are increasingly becoming targets of violence by the new breed of casseurs (wreckers) who attach themselves to otherwise peaceful gatherings and go on the rampage. Until fairly recently, the main risk in reporting unruly demonstrations was being batoned or tear-gassed by the feared CRS riot squads - no respecters of press credentials - but now photographers and camera crews working in the crowds face a different threat.

'There's a frightening level of hostility towards the media among the kids from the poor suburbs who come to marches looking for trouble,' says Sylvie Languin of the Rapho picture agency. Well before the Gamma story broke, journalists found themselves being abused and shoved around by youths accusing them of conniving with the police. 'It's pointless to reason with them, you just shoot and get out while your cameras are still in one piece,' says a veteran news photographer who was hit by a half-brick on his last assignment at a demonstration.

In these charged circumstances, the management at Gamma - one of whose staff photographers had been badly hurt at an earlier demonstration - reacted angrily to the Globe story, accusing the Paris police of acquiring its material by 'irregular means' and of using the two photographs without permission, alongside other images taken by police video crews. 'The journalist's work must never be confused with that of the police,' declared the agency's editor-in-chief, Didier Contant, rejecting the notion that someone inside Gamma might have handed over the prints on the quiet.

An apology of sorts by the Prefecture followed, but by then the affair had taken a new and, for Gamma, embarrassing turn. As Parisian journalists scurried to sign a petition emphasising that their professional creed must be 'information, not denunciation', it emerged that the agency routinely supplied photographs for use in a police house magazine.

Worse, half a dozen prints taken at the demonstration in question, all showing the faces of casseurs, had found their way to a special police intelligence service. Insiders there told the newspaper Liberation that 'a correspondent' inside Gamma had indeed slipped them the material, purportedly for use in assembling 'sociological profiles' of rioters.

Mr Contant acknowledged that a mistake had been made in releasing the riot material without obscuring the features of those depicted. 'With hard news, we don't always have time to do that,' he explained.

In Globe's next bite at the story, an unidentified police officer claimed that orders had come from the top to 'neutralise' the casseurs by any means. Two- man teams in plain clothes were being deployed, one photographing or filming, the other watching his back, and 'they don't hesitate to use television network stickers as camouflage'.

At the end of last week, a terse communique from Gamma announced that Mr Contant and the agency's editorial director, Floris de Bonneville, had been 'negligent and imprudent' in their handling of a highly sensitive affair. Both have received 'protective' notice of dismissal.